Ye shall ask me nothing (εμε ουκ ερωτησετε). Either in the sense of question (original meaning of ερωταω) as in verses John 16:19; John 16:30 since he will be gone or in the sense of request or favours (like αιτεω in this verse) as in John 14:16; Acts 3:2. In verse John 16:26 both αιτεω and ερωταω occur in this sense. Either view makes sense here.

If ye shall ask (αν τ αιτησητε). Third-class condition, αν like εαν with first aorist active subjunctive of αιτεω. Note John 14:26 for "in my name."